Process for producing potato chips

ABSTRACT

Fried potato particles, frequently identified as potato chips or French fries, are prepared having an acceptable color, one from Color 4 through 7 of the Color Reference Standard of the International Potato Chip Institute by a method comprising freezing raw sliced potatoes followed immediately thereafter by thawing said slices in warm water and frying the thus treated slices.

McCready .99/207 0 United States Patent 1 1 3,660,l 13 Ng 1 1 May 2,1972 1541 PROCESS FOR PRODUCING POTATO 3,175,914 3/1965 Vahlsing..99/10o CHIPS 3,355,299 11/1967 McLaughlin... .....99/l93 3,397,9938/l968 Strong t ..99/l93 Inventor Chock 11. 1020 Merced Street,3,484,252 12/1969 Popeil 1 ..99/193 Berkeley. CaHf- 94707 2,983,6195/1961 Sbaw ..99/193 2 'l 2 197 [2 1 Fl ed Jan 0 Primary Examiner-NormanYudkofl' [2l] Appl. No.: 5,966 AssistanrExaminer-Manin G. MullenAttorney-Eckhoff and Hoppe [52] U.S.Cl ..99/100P,99/l03,99/l93 [57]ABSTRACT [51] ..A23l 1/12, A23b 7/04 58 Field of Search ..99/100, 103,193, 207 Fried potato particles, frequently identified as Potato chipsor French fries, are prepared having an acceptable color, one [56]References m from Color 4 through 7 of the Color Reference Standard ofthe International Potato Chip Institute by a method compris- UNITEDSTATES PATENTS ing freezing raw sliced potatoes followed immediatelythereafter by thawing said slices in warm water and frying the 2,597,0655/1952 Chase ..99/l93 thus treated slices 2,597,067 5/1952 Chase..99/l00 2 Claims, No Drawings PROCESS FOR PRODUCING POTATO CHIPSBACKGROUND OF THE INVENTION It has long been recognized that potatoeshaving a substantial reducing sugar content produce an undesirable colorwhen deep fat fried in particle forms. The problem provided by reducingsugars is particularly present when the potatoes have been stored at alow temperature as is frequently the case. It has been proposed to treatsuch potato particles with various chemicals, such as calcium ormagnesium salt solutions, various organic acid, an aqueous solutioncontaining sulfur dioxide, a solution of common salt and sodium citrate,various sugar solutions and a sodium bisulfite solution.

SUMMARY OF THE INVENTION I have found that by freezing the potatoparticles under such conditions that ice crystals form in the individualcells and so rupture the cells, due to the increase in size resultingfrom freezing of the water present, and thereafter thawing the potatoparticles in warm water, the cell contents released upon cell ruptureand thereafter frying the particles, the particles are reduced in colorby two or three units on the aforementioned International Potato ChipInstitute Color Reference Standard as compared to fried particles whichhave not been so prepared.

It is in general the broad object of the present invention to provide animproved process for treating potato particles before frying,particularly those produced from potatoes which have been stored at alow temperature.

Another object of the invention is to produce deep fat fried potatoparticles from potato tubers of low specific gravity and having a highreducing sugar content.

A further object of the invention is to produce light and uniformlycolored deep fat fried potato products regardless of the variety of thepotato tubers or the time of the year.

The invention includes other objects and features of advantage, some ofwhich, together with the foregoing, will appear hereinafter wherein thepreferred process of this invention is disclosed.

DESCRIPTION OF THE PREFERRED EMBODIMENT In one embodiment typical of thepresent invention, potato tubers which had been stored at a lowtemperature were peeled and washed in the usual manner. The potatoeswere then sliced and washed free of the starch released. The washedparticles were then subjected to a temperature of between 0 and 25 F.for a time sufficient to freeze the potatoes. This can be achieved by acold air blast, application of liquid nitrogen or freon in any othersuitable manner. Immediately after freezing, the frozen particles wereimmersed in warm water at a temperature between and F. for from 1 to 3minutes, the temperature and time being sufficient to thaw the potatoes.Simultaneously, the cellular content of the ruptured cells in the potatoslice was released during thawing. To effect this, the wash water usedfor thawing was changed constantly. After thawing, the particles werethen fried under the usual frying conditions at a temperature between350 and 375 F. in a frying oil. Upon completion of the process, it wasfound that the color of the product had been improved from two to threeunits on the Color Reference Standard as compared to those of a controllot which had not been subject to the process steps of this invention.

From the foregoing, I believe it will be apparent that I have provided anovel, simple and improved. process for the treatment of potato slices,particularly those produced from potatoes which have been subjected tocold storage and which have a high reducing sugar content and lowspecific gravity.

lclaim:

l. A method of treating sliced potatoes, the natural sugar content ofwhich is such that the desired color change cannot be attached when theslices are cooked by frying which method comprises freezing the rawsliced potatoes to form ice crystals in the cells of the potatoes and sorupture the cells, immechately thereafter, thawing the potatoes in warmwater to melt the ice crystals and extract the contents of cells whichwere ruptured upon formation of the ice crystals, and frying the thustreated slices in a frying medium at a temperature in the range of 350375 F.

2. The method of claim 1 wherein the particles are frozen at atemperature between 0 and 25 F. and thereafter the slices are thawed inwater at a temperature between 90 and 120 F. for from 1 to 3 minutes.

i i t t t

2. The method of claim 1 wherein the particles are frozen at atemperature between 0* and 25* F. and thereafter the slices are thawedin water at a temperature between 90* and 120* F. for from 1 to 3minutes.